| SMT Consultancy Limited | Information & communication | 2022 |
| Snappers Limited | Health & social care | 1989 |
| Sneham Properties Limited | Real estate | 2024 |
| Sneham Solutions Limited | Information & communication | 2018 |
| Snowball Revenue Services Ltd | Information & communication | 2023 |
| Snowdonia Evans Investment Management Limited | Education | 2013 |
| SNT Advisory Ltd | Professional & scientific | 2026 |
| SO41 Ltd | Manufacturing | 2021 |
| Soap LLP | | 2014 |
| Soaring Surveys Limited | Professional & scientific | 2019 |
| Sobo Systems Limited | Information & communication | 2025 |
| Social Change Consulting Limited | Professional & scientific | 2020 |
| Sock Drawer Coding Limited | Information & communication | 2015 |
| Softstyle Ltd | Information & communication | 2025 |
| Software Design & Consulting Limited | Information & communication | 2018 |
| Software Experience Limited | Information & communication | 2010 |
| Software Support Products Limited | | 1984 |
| SOJ Fire Limited | Public administration | 2018 |
| SOL Aura Ltd | Other services | 2025 |
| Solace Communications Ltd | Other services | 2024 |
| Solaire Solutions Limited | Professional & scientific | 2018 |
| Solar Groundwork Services Limited | Construction | 2025 |
| Solas Education Group Ltd | Education | 2026 |
| Sole Group Limited | Information & communication | 2017 |
| Solent Lettings Ltd | Real estate | 2022 |
| Solidscript Limited | Information & communication | 2018 |
| Solutionise Ltd | Information & communication | 2023 |
| Solve Consult Ltd | Information & communication | 2021 |
| Solvixa Consulting Ltd | Administrative & support | 2025 |
| Solweb Limited | Information & communication | 2000 |
| Somchand Solutions Limited | Administrative & support | 2019 |
| Somerley Golf Limited | Arts & recreation | 2003 |
| Somerset Legal Ltd | Professional & scientific | 2021 |
| Sommartel Ltd | Professional & scientific | 2019 |
| Somnium Digital Ltd | Information & communication | 2012 |
| Somnium Domos Limited | Real estate | 2022 |
| Somnum Sounds Ltd | Information & communication | 2022 |
| Sonder PS Ltd | Professional & scientific | 2014 |
| Sonnaz Limited | Wholesale & retail | 2023 |
| Sonnaz Media Ltd | Information & communication | 2020 |
| Sonner Design Ltd | Construction | 2024 |
| Sonosphere Limited | Professional & scientific | 2018 |
| Sopers Lane Ltd | Real estate | 2024 |
| Sophie Cowdrey Design Ltd | Professional & scientific | 2024 |
| Sorrels Caterers Limited | Hospitality | 2011 |
| Sotam IT Consultancy Limited | Information & communication | 2015 |
| Soundcomplete Ltd | Manufacturing | 2021 |
| Sourcing Management Limited | Professional & scientific | 2024 |
| South Bay Limited | Manufacturing | 2018 |
| South Building Services Ltd | Construction | 2020 |
| South Central Dance Ltd | Education | 2021 |
| South Coast Artificial Grass Limited | Administrative & support | 2019 |
| South Coast Bespoke Ltd | Construction | 2024 |
| South Coast Boiler Services Ltd | Construction | 2013 |
| South Coast Builders Ltd | Construction | 2021 |
| South Coast Homes Limited | Construction | 1984 |
| South Coast Ice Limited | Wholesale & retail | 1997 |
| South Coast Project Management Ltd | Construction | 2025 |
| South Coast Surveyors Ltd | Construction | 2023 |
| South Heat & Electrical Ltd | Construction | 2009 |
| South Lytchett Manor Caravan and Camping Park Limited | Hospitality | 2009 |
| South of England Leisure Limited | Arts & recreation | 2009 |
| South West Consulting Partners Limited | Professional & scientific | 2021 |
| South West Marine Services Ltd | Manufacturing | 2023 |
| South West Parcel Partner Limited | Transport & logistics | 2022 |
| South West Regional Assessment Centre Limited | Education | 1996 |
| Southern Access Services Ltd | Construction | 2023 |
| Southern Audiology Solutions Limited | Health & social care | 2018 |
| Southern Concrete Services Ltd. | Construction | 2004 |
| Southern Construction Solutions Limited | Construction | 2019 |
| Southern Fire Doors Ltd | Manufacturing | 2012 |
| Southern Liquid Roofing Ltd | Construction | 2018 |
| Southern Ltd | Construction | 2026 |
| Southern RV Hire Ltd | Administrative & support | 2019 |
| Southern Sheet Piling Ltd | Construction | 2007 |
| Southern Technical Fabrications Limited | Manufacturing | 1992 |
| Southern Works Limited | Energy | 2013 |
| Southwest Angling Supplies Limited | Wholesale & retail | 2012 |
| Sowp Ltd | Manufacturing | 2020 |
| SP4 Group Ltd | Administrative & support | 2019 |
| Spa DE LA Mare Ltd | Construction | 2002 |
| Spacecell Enterprises Ltd | Information & communication | 2025 |
| Spanish Homemade Limited | Hospitality | 2016 |
| Spark IO Ltd | Information & communication | 2024 |
| Sparks & Co Financial Services Limited | Financial services | 2004 |
| Sparrow Contracting Ltd | Information & communication | 2022 |
| Sparrowhawk Engineering Ltd | Professional & scientific | 2022 |
| Spartan Creations Ltd | Wholesale & retail | 2023 |
| Spec 2003 Limited | Construction | 2002 |
| Special Products for Special Cakes Ltd | Wholesale & retail | 2023 |
| Specialised Vehicle Services Limited | Wholesale & retail | 2005 |
| Specialised Vessel Services (UK Technical Services) Ltd | Manufacturing | 2015 |
| Specialist Motorworx Ltd | Wholesale & retail | 2021 |
| Specialist Piling Solutions Limited | Construction | 2016 |
| Specialist Print Services Ltd | Manufacturing | 2018 |
| Spectacular Future LLP | | 2008 |
| Spectacular Software Limited | Information & communication | 2026 |
| Spektrum Consulting Limited | Information & communication | 2025 |
| Spellman Solutions Limited | Information & communication | 2020 |
| Spence Brothers Ltd | Extraterritorial | 2018 |